Single Ventricle Reconstruction Follow-Up – SVR 3 (Observational Study)

As a baby, your child was enrolled in the Single Ventricle Reconstruction (SVR) trial which aimed to see which shunt type was best for infants with single ventricle heart defects undergoing the Norwood operation. Your child received one of two kinds of shunts; a modified Blalock-Taussig shunt (MBTS) or right ventricle to pulmonary artery shunt (RV-to-PA shunt) as part of that study.

You/your child then had the option to enroll in the Single Ventricle Reconstruction Extension study (SVR II)as we aimed to learn how children 2-6 years of age do with each of these shunt types and to improve our understanding of the medical and surgical factors which influence health and development for children with single ventricle heart disease.

We are now inviting you to join this study which is a continuation of the two previous SVR studies. The purpose of this study is to see which type of shunt placed at the time of the Norwood operation is most effective by later school age, beginning at 10 years of age. We want to learn if there are any long term differences in heart function, exercise ability, neurodevelopment, or quality of life between children who received a MBTS and those who received an RV-to-PA shunt.

This study is being performed with the support of the Pediatric Heart Network at all sites which participated in the original SVR trial. The study began in the summer of 2015.

Who can be in the study?

This study is enrolling children who participated in the original SVR study. As a part of the SVR study cohort, your child is one of the largest groups of children with single ventricle heart disease, and has helped to answer important questions already.

What do we have to do to be in the study?

The study will be explained to you in detail by one of the study investigators. Once your questions have been answered, you will be asked to sign an informed consent form to enter the study. If you give permission for your child to participate in this study, we will invite your child to come to the hospital where his or her heart surgery was done or to another closer hospital participating in this study. During your visit your child will have:
Medical history, including height and weight measurement;
  • A cardiac magnetic resonance imaging (CMR);
  • A cardiac echocardiogram;
  • A bicycle exercise test; and 
  • Neurodevelopmental testing including puzzles, games and paper and pencil tools to evaluate learning and development.
After the study visit, a member of the study team will contact you yearly until your child is 16 to update your child’s medical history data for the study.

How long will we be in the study?

Your child’s participation in the study will be from the time of the study visit until he or she turns 16.

What are the possible benefits to being in this study?

Your child may receive no direct benefit from the study tests. However, the possible benefits of participation are as follows:
  1. You and your child will learn about how your child is learning and developing. If there are areas in which your child is having difficulty, these can be identified and recommendations for further evaluation or intervention provided, as appropriate. 
  2. Your child’s cardiac MRI will be reviewed by a cardiologist. We will communicate to you any abnormal findings and forward the results to your child’s primary care physician with your permission. Further referrals to appropriate clinicians will be made as appropriate. 
  3. It is possible that the clinical assessments obtained for research purposes, including the cardiac MRI, echocardiogram, exercise test and neurodevelopmental evaluation, may reveal important clinical findings. 
  4. There might be an indirect benefit from the awareness that through your participation, these study results may help to improve the care of children with similar problems in the future. 

What are the possible risks to being in this study?

Cardiac Magnetic Resonance Imaging (CMR):
MRI uses a powerful magnet to make images. Therefore, persons with metal implants, such as certain types of surgical clips or pacemakers should not have an MRI. Other metal objects such as keys, pocketknives, or some types of jewelry must be removed prior to entrance to the magnet room. These objects can be pulled towards the magnet at very high speeds and can cause serious injury. You will be screened for such objects. In addition to a large magnet, the MRI scanner also uses radio frequency waves that can, on rare occasions, cause a mild warming sensation similar to what you feel on a warm day at the beach. The MRI scanner makes loud banging noises during the scanning session. During the MRI study your child will be provided with earplugs to reduce the noise heard from the scanner. It is also possible that the magnetic fields in the scanner can cause mild nerve and muscle twitching in the arms and legs. Such effects are extremely rare but possible. Some people simply find it uncomfortable and/or claustrophobic to lie in the close space of the MRI scanner. If during the MRI, your child gets nervous or upset, the procedure will be stopped.

Although there are no known long-term harmful effects from having an MRI scan performed, it is always possible that there are long-term effects that are not presently known.
During the MRI procedure, wires may be attached to your child to monitor breathing and heart rate. On very rare occasions the presence of such wires has resulted in burns at the site of skin contact. Proper placement and use of the wires greatly minimizes this risk and the technologists have been trained in this procedure so that the probability of a skin burn from the wire contacts is very small. 

The MRI suite has developed techniques for making the MRI scan comfortable. We will use form-fitting pillows to keep you/your child’s head still and comfortable. A magnet-compatible sound system, including audio headphones will permit us to talk to your child and for your child to talk to us during the study. An attendant will be next to your child throughout the scan. This will make it less likely for your child to move his or her head, as well as make your child feel more comfortable and satisfied. In addition, your child may have the opportunity to watch a movie and/or to listen to music while participating in the MRI. We will not perform this test on your child if sedation is necessary for him/her to stay still. If your child declines to undergo MRI, he or she can still be included in other portions of this study.

Exercise Testing:
Exercise testing for this study will involve pedaling on a stationary bike at increasing intensity. Your child will be asked to pedal as fast as he or she can. A small number of individuals who have had a Fontan operation develop an abnormal heart rhythm with strenuous exercise. Monitoring the heart’s rhythm during the test will tell us whether this occurs and will help us learn how to care for your child. A member of the exercise testing team will be present throughout the test to continuously monitor your child’s heart rhythm and how your child is doing.

There are few risks to your child having an echocardiogram except that he/she may feel bored.
Neurodevelopmental Testing:
The neurodevelopmental testing will require approximately 5 to 6 hours. During this time there is a small chance that your child will feel frustrated by some of the evaluation but the person who will be conducting the testing is trained to work with children on these activities and will help avoid any frustration.

The MRI, echocardiogram, exercise testing and neurodevelopmental evaluation will all be done by experts who are used to working with children.

Of note, your child’s cardiac MRI and echocardiograms and MRI will be sent to Pediatric Heart Network core laboratories at Cincinnati Children’s Hospital and Children’s Hospital of Wisconsin. Every effort will be made to remove identifying information from these studies before they are sent, but in rare cases, your child’s information might be left on them. If information potentially revealing your child’s identity cannot be removed from these studies prior to sending them to the core labs, the core labs will remove all identifying information before the images are reviewed. The de-identified echocardiograms and cardiac MRIs will be stored on secure servers for analysis. These files will be treated confidentially at these laboratories and kept in secure databases. Your child’s personal identifying information will not be kept in any other records outside of this institution.

What are the costs to me to be in the study?

There will be no extra costs to you when you join this study. You must pay for all other costs related to your normal medical care such as hospital stays, surgery, drugs, lab tests, and doctor's fees which are thought to be standard medical care for patients with your condition.